Mobile communications networks are in the process of offering increasingly sophisticated capabilities associated with the motion and/or position location sensing of a mobile device. New software applications, such as, those related to personal productivity, collaborative communications, social networking, and/or data acquisition, may utilize motion and/or position sensors to provide new features and services to consumers. Moreover, some regulatory requirements of various jurisdictions may require a network operator to report the location of a mobile device when the mobile device places a call to an emergency service, such as a 911 call in the United States.
Round trip time (RTT) measurement techniques can be one way to accurately determine position. These techniques typically involve knowledge of time delays incurred by the wireless signals as they propagate through various network devices, such as wireless access points (APs), comprising the network. Such delays may be spatially variant due to, for example, multipath and/or signal interference. Moreover, such processing delays may change over time based upon the type of network device and/or the network device's current networking load. Because these processing delays can be substantially larger than other aspects of RTT measurements (e.g., time of flight), accurate processing delay estimates are important in obtaining accurate position determinations using RTT measurements.